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    SubjectRe: USB performance bug since kernel 2.6.13 (CRITICAL???)
    On Thu, 2006-10-12 at 12:33 -0700, Open Source wrote:
    > I am using a device that submits URBs asynchronously using the libusb
    > devio infrastructure. In version 2.6.12 I am able to submit and reap
    > URBs for my particular application at a transaction rate of one per
    > millisecond. A transaction consists of a single WRITE URB (< 512
    > bytes) followed by a single READ URB (1024 bytes). Once I upgrade to
    > version 2.6.13, the transactional rate drops to one per 4
    > milliseconds!

    The kernel's internal tick rate was lowered from 1000Hz to 250Hz
    starting with 2.6.13. Rebuild with CONFIG_HZ=1000 and the performance
    should return to normal.


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      Last update: 2006-10-12 21:57    [W:0.023 / U:23.916 seconds]
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